Aphids & Clematis

In addition to aphids, scales, thrips and whiteflies can infest clematis vines.

The delicate blooms of the clematis vine add color to your garden and curb appeal to your home. Clematis (Clematis spp.) are deciduous evergreen vines that can produce flowers in a range of colors. Clematis vines prefer cool winters or areas that have a coastal effect, but most varieties can grow well in areas of the country within Sunset's Climate Zones A2, A3, 2 through 11, 14 through 24 and 28 through 41. They require full sun and regular water to thrive, but can also fall prey to aphids. Aphids are tiny pests that can cause unsightly damage to clematis vines and blossoms. Early detection and introducing immediate control methods will limit damage and protect the health of the vines.

Aphids

Aphids are tiny insects with soft bodies and needle-like mouth parts that work like straws to cause damage to the foliage and flowers of certain plants. Almost all species of aphids have cornicles, which are small tubes that grow out of the back of their bodies. Look for these to correctly identify pests as aphids. Aphids can be green, black, brown, red, pink or yellow, depending on what species they belong to. The pests almost always feed in groups, which makes them easier to see, but also makes it more difficult to get rid of them.

Damage

When aphids feed on clematis, they can cause damage to both the leaves and the petals. As the pests suck moisture and nutrients from the soft tissues of the clematis, it can cause the leaves to curl, turn yellow and become distorted. The damage can also cause stunted growth. Aphids leave behind sticky honeydew, which turns black as sooty mold grows on the foliage of the clematis. Aphid populations increase rapidly, which makes damage more prevalent and widespread.

Solution

One of the most effective ways to control aphids on clematis vines is to rinse them with a strong stream of running water. A strong stream of water will knock the aphids from the foliage and will also rinse away honeydew. Often, this prevents the aphids from returning to the clematis vine. Rinse them away in the early morning so the clematis vine can dry thoroughly during the day, which will decrease the risk of fungal diseases. Predatory insects, such as ladybugs and parasitic wasps, help control an aphid infestation by eating the tiny pests. Horticultural oil and yellow sticky traps might also destroy aphids.

Prevention

Weed control is one way to prevent aphids from infesting clematis vines. Certain types of weeds, such as sowthistle and mustards, attract aphids, which increases the chances of infestation on healthy plants growing nearby. If you grow clematis vines where these weeds grow, aphids can migrate to the vines and begin to feed on them. Limiting application of nitrogen-based fertilizer can also reduce the risk of an aphid infestation. Aphids flourish in areas where large amounts of nitrogen-based fertilizer is applied.

About the Author

Sara Ipatenco has taught writing, health and nutrition. She started writing in 2007 and has been published in Teaching Tolerance magazine. Ipatenco holds a bachelor's degree and a master's degree in education, both from the University of Denver.